Researchers experiment with oilfield wastewater to irrigate crops

by Brandon Mulder bmulder@mrt.com

Published 12:44 pm, Thursday, January 14, 2016

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Water gushes out of a drilling pipe as it is pulled up to be replaced with a fresh pipe at a hydraulic fracturing site in Midland, Texas, Sept. 24, 2013. The drilling method known as fracturing uses huge amounts of high-pressure, chemical-laced water to free oil and natural gas trapped deep in underground rocks. With fresh water not as plentiful companies have been looking for ways to recycle their waste. (AP Photo/Pat Sullivan)

Water gushes out of a drilling pipe as it is pulled up to be replaced with a fresh pipe at a hydraulic fracturing site in Midland, Texas, Sept. 24, 2013. The drilling method known as fracturing uses huge

Last November researchers harvested an experimental cotton crop, one irrigated to maturity by treated oilfield wastewater. It may sound like an unusual proposition, but results, which are expected to be fully released later this month, point to exceptional success.

The project aims at creating a new way of recycling hydraulic fracturing wastewater, also known as produced water, by diverting it from injection wells to the farm fields. Down in the Trans-Pecos region, Texas A&M AgriLife researchers and the water conservation technology company Energy Water Solutions sowed 4 acres of the crop last spring.

The controlled experiment included some crops that were watered with normal irrigation water and crops that were watered with a water and wastewater blend, according to Bob Avant, Texas A&M AgriLife Research director.

“Statistically, there was no difference-the cotton’s quality and the quantity remained the same,” Avant said. The only perceivable difference was the color and condition of the plants’ foliage. “Once the data came in, there was no statistical difference at all between the treated and untreated in both yield (bales per acre) and quality (boll strength).”

The wastewater was provided by Anadarko Petroleum, which operates several oil and gas wells throughout the Delaware Basin, according to a press release. The water is passed through a reverse-osmosis system that treats the water to a near potable level, then is blended with typical irrigation water, which usually has higher levels of dissolved solids. The result, according to Avant, is a solution cleaner than pure irrigation water.

In a state not unfamiliar to the pressures a drought can put on both agriculture and energy industries in West Texas -- where an average of one barrel of oil is accompanied by 10 barrels of produced water, according to EPA data -- conservation strategies like this will likely become more necessary with time, Avant said.

“We need to be able to better use all sources of water for beneficial needs” and provide a new alternative option to injecting produced water back down a well, he said. “Everything else is just going to be a sunk cost, if you will.”

Although a first of its kind in Texas, water researchers in California have already spent two decades experimenting with irrigating food crops with wastewater, according to the environmental reporting website Circle of Blue. On Tuesday, a food safety panel gathered to discuss the potential hazards of consuming wastewater irrigated produce -- a subject Texas researchers are far from considering.

“The (Texas) regulators and oil companies are more nervous about it than we are in terms of trying it. We think it would be worth trying, just to see if anything would show up in a cantaloupe or something like that,” Avant said. “The reason we chose cotton was because (the Railroad Commission) didn’t want us testing on anything that was viewed as a food crop.”

However trepidatious state regulators are, they have so far been supportive of these efforts.

“I have always said that the only thing more important to the economic future of Texas than oil and gas, is water,” said RRC Chairman David Porter in a press release last fall. “The Railroad Commission updated its rules to remove regulatory barriers that hundred operators from developing innovations that encouraging water recycling and conservation.”

The Trans-Pecos project is expected to continue next growing season, when researchers will continue studying the effects more-toxic blends have on the cotton crops.